Right now the adventuring tree sucks. It could be that it is not fully enabled or because the other tress like civics are out it prevents some of the options appearing. Also things like dungeons don't seem to be functioning
First off dungeons. I have no idea how these are supposed to be implemented with a dungeon keepers guild and a questing tech called dungeon delving, but it seemed to me that you could train or hire a dungeon keeper who could then establish a dungeon which at some point you could go and explore and get cool loot from. If I am wrong correct me.
Preamble: I think ruins, dungeons, quests etc should have a difficulty rating of some kind. whether it's a number system of 1 to 5 or even just easy, intermediate and hard it would be beneficial both for the players and for game mechanics.
This is how I think Dungeons should work. You get the dungeon keeper's guild and hire/train a dungeon keeper. You can then make him go off somewhere and establish a dungeon. After say 5 truns it becomes an easy dungeon with applicable rewards and difficulty, after 20 turns it upgrades to the next highest and then 30 turns later one level higher etc. This adds the whole decision of how soon do you reap the rewards of your investment. Also other players should be able to visit your dungeons too, also adding another interesting aspect that it may be stolen from under you.
So you don't just build the dungeon next to your city and go cheesy, dungeons cannot be built in controlled land. What's more if controlled land over takes a dungeon it should disappear, removed by the local populace for harbouring dangerous creatures. Higher level dungeons should spawn random wandering creatures too which gives a reason to keep them going and maybe punishing caravan routes etc, and could be a very strategic asset if an opposing player cannot clear it.
Ok so back to the Adventuring tree.
Green: Questing (Huts and so forth)
Yellow: Ruin exploring, Delegation (Champions can perform quests on your behalf), Treasure hunter (you have a chance of better loot from exploring dungeons or quests)
Red: Dungeon Delving, Feats (sovereign and champions get an amount of bonus experience for completing quests), Trailblazer (A group with a unit on a current quest gets increased movement)
Yellow: Assassins guild, Dungeon Keepers guild, Guild of Heroes (small percent chance of a hero offering to join your kingdom each turn, requires "Pub" from civics), Mediator (15% of price of heroes)
Red: Guild of Champions (small chance of recruiting higher level champions, requires "Pub" from civics), Negotiator (20% of price of heroes), Dungeon Overseer (basically a dungeon keeper but with faster progression).
Green: Heroes (I presume this lets recruit adventurers instead of the basic guys, level 1-2)
Yellow: Legends (the ability to recruit higher level adventurers level 1-5), Tithe (Adventurers can learn a merchant skill to give small amount of giler per turn), Productive (adventurers can learn a production skill to give materials per turn), Mining (adventurers can learn a skill to contribute metal per turn), Harvest (Adventurers can learn a farming skill that allows them to give food resources per turn).
Red: Titans (recruit high level champions level open ended), Deliverance (your heroes have a small chance of escaping a combat where they would otherwise have died)
I have seen that hero skill trees are coming, and I have included examples of skill that could be opened up with the hero tree. It would be great to make the best skills available to heroes only through unlocking the adventuring tree. This tree would have me seriously confused between the 4 trees we have seen. I would have to try different ones every game!